Filament wound crew rest enclosure structure

ABSTRACT

A mobile platform personnel berth unit and a method for creating the mobile platform personnel berth unit are provided. A male mandrel is created defining an inner mold line surface of the berth unit. The male mandrel is overlayed with one or more layers of filament strips. The filament layers are thermally cured to create an integrated structural member. The male mandrel is then removed from the structural member. The structural member is profile shaped to create a semi-finished berth unit having a top, a bottom and a pair of integral side panels. Additional entrance and back panels as well as access panels and connecting hardware are then added to complete the berth unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Ser. No. 10/943,034, filed Sep.16, 2004, the disclosure of which is hereby incorporated by referenceinto the present application.

FIELD

The present disclosure relates in general to mobile platform crew restberth units and more specifically to an aircraft crew rest enclosurestructure and method of manufacture.

BACKGROUND

Mobile platforms including aircraft, trains, ships, etc. often providerest areas for crew or passengers when the vehicle is intended foroperation over lengthy time periods. For simplicity, applications foraircraft crew rest berths are generally described herein. Crew restberths are enclosures generally provided for an individual to rest orsleep in private, often having curtains or doors, electrical supplyoutlets, entertainment outlets, etc. Commercial aircraft in particularare required to provide crew rest spaces for aircraft which operate overextended periods of time. Common crew rest areas include bunks orberths, seats, and lavatories for crew use. Aircraft crew rests areoften separately provided for flight crew members and for flightattendants.

The berth units are frequently built up using fiberglass/honeycombpanels that are joined to form a module. Separate top, bottom and sidewalls are prefabricated. The walls are connected using multiplebrackets, fasteners and fittings. An upper and/or lower support plate iscommonly used to support one or more berths to structure of the mobileplatform. This construction/installation technique is labor intensiveand produces berth units having multiple joints and undesirably highweight. In addition, sub-assembly of the units to the support plate(s)normally must take place on-site on the aircraft during construction,which provides additional delay in construction.

It is often a complex process to install crew rest berths on mobileplatforms such as aircraft due to the size and weight of the berths,which can be about 300 pounds. This weight necessitates use of on-sitespecial lifting/handling equipment. The structure to support a berth ofthis weight must also be reinforced or require multiple attachmentpoints to carry not just the dead weight of the berth and supportplates, but also the dynamic load of the berth due to berth/platformmotion and aircraft motion. Access for installation of crew rest berthsis also limited by items such as piping, structure, environmentalcontrol system ducting, flight control cabling, fire detection systems,stow-bin support structure and center stow-bins, and electrical cablingpositioned adjacent to or passing through the crew rest areas.Installation of all these items needs to be coordinated duringconstruction of the aircraft.

Crew rest berths have been positioned in the overhead volume (above themain cabin ceiling) of aircraft, which offers the potential forincreased passenger or cargo capacity to the airline operator. Overheadpositioned rest units do not displace main deck seats or cargo containervolume in the lower lobe, and so increase the volume within the fuselagethat is available for revenue service. Existing overhead positioned restunits, however, are excessively heavy as noted above and thereforereduce the payload potential of the aircraft.

A further disadvantage of existing crew rest berths is that assemblysequencing of these items is predetermined and therefore installation ofcrew rest berthing affects the overall construction schedule of theplatform or aircraft. The additional structure and special equipmentrequired to construct and install existing berths adds weight,complexity, and cost and therefore increases installation time,negatively affecting the construction schedule. Access space for theinstalling mechanics and any special equipment is also required. A crewrest berth design providing lower weight as well as faster and simplerinstallation is therefore desirable.

SUMMARY

According to one embodiment of the present disclosure, a method forcreating a filament wound crew rest enclosure structure includesselecting a male mandrel defining an inner mold line surface of theberth unit. The male mandrel is overlayed with a plurality of adjoiningfilament strips. The filament strips in one or more layers are autoclavecured to create an integrated structural member. The male mandrel isthen removed from the structural member. The structural member isprofile shaped to permit installation of additional front and backpanels as well as access panels and connecting hardware which completethe berth unit.

According to another embodiment of the present disclosure, a mobileplatform personnel berth unit includes a body having integrally joinedperimeter walls defining a substantially hollow interior space. A wallthickness is formed from a plurality of wound filaments. In onepreferred embodiment, a material of the body is a graphite composite.According to yet another preferred embodiment of the present disclosure,a core ply is inserted between layers of the filament strips to stiffenthe wall and provide attachment points for additionalequipment/fasteners.

A filament wound crew rest enclosure structure of the present disclosureprovides several advantages. By integrally forming the walls, top andbottom surfaces of a crew rest enclosure, the number of connectingfittings is reduced. By using one or more filament wound layers of agraphite or graphite/polymeric material composite, a weight of the crewrest enclosure can be reduced to about 75 pounds or less, which permitstwo mechanics to install the crew rest enclosure by hand without theneed for special handling equipment. By using an automated computercontrolled tape laying machine, construction complexity is reducedcompared to the known process of forming individual panels and joiningthe panels using a plurality of connectors and fasteners.

The features, functions, and advantages can be achieved independently invarious embodiments of the present disclosure or may be combined in yetother embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a perspective view of a filament wound crew rest enclosurestructure according to a preferred embodiment of the present disclosure;

FIG. 2 is a perspective view similar to FIG. 1 further showing a malemandrel supporting an integrated structure for the crew rest berth ofone preferred embodiment of the present disclosure;

FIG. 3 is a perspective view of a filament application device used towind individual filaments of material about the male mandrel of thepresent disclosure;

FIG. 4 is a perspective view of an exemplary male mandrel of the presentdisclosure having a partially completed plurality of filament stripswrapped thereon;

FIG. 5 is a partial cross-sectional view taken at Section 5-5 of FIG. 4;

FIG. 6 is a partial cross-sectional view similar to FIG. 5 showinganother preferred embodiment of the present disclosure;

FIG. 7 is a partial cross-sectional view similar to FIG. 5 showing yetanother preferred embodiment of the present disclosure;

FIG. 8 is a partial cross-sectional view similar to FIG. 5 showing yetstill another preferred embodiment of the present disclosure;

FIG. 9 is a perspective view of a berth assembly of the presentdisclosure having a pair of joined berths supported from structure of amobile platform;

FIG. 10 is a perspective view generally showing a underside view lookingforward of a single crew rest berth of the present disclosure;

FIG. 11 is a cross sectional view taken at section 11-11 of FIG. 10;

FIG. 12 is a flow diagram of exemplary operations for creating a mobileplatform personnel berth of one embodiment of the present disclosure;and

FIG. 13 is a flow diagram of exemplary operations for creating a mobileplatform personnel berth of another embodiment of the presentdisclosure.

DETAILED DESCRIPTION

The following description of the various embodiments is merely exemplaryin nature and is in no way intended to limit the present disclosure, itsapplication, or uses.

Referring generally to FIG. 1 and according to one embodiment of thepresent disclosure a crew rest berth 10 includes an upper first wall 12,a lower second wall 14, a first side wall 16 and a second side wall 18.First and second side walls 16, 18 generally oppose each other and areshown in FIG. 1 configured in parallel to each other. The presentdisclosure is not limited to the specific geometry shown in FIG. 1. Acrew rest berth 10 of the present disclosure can be formed in anygeometric shape suitable for application of the filament strips of thepresent disclosure. An end connection 22 is machined into or provided onat least one end of crew rest berth 10. End connections 22 are adaptedto support end panels not shown in this view for clarity. A cavity 20 isformed substantially throughout crew rest berth 10 bounded by each offirst and second walls 12, 14 and first and second side walls 16, 18 andthe end panel(s).

Crew rest berth 10 includes a berth length “A”, a major height “B” and aminor height “C”. Dimensions “A”, “B” and “C” are predetermined based onthe geometry of the mobile platform in which crew rest berths 10 areinstalled. In a preferred embodiment of the present disclosure, berthlength “A” is approximately 2.44 meters (8 feet). This length providesample space for a person occupying crew rest berth 10 with additionalroom for necessary personal items.

Referring now to FIG. 2, an integrated structure 23 formed about anexemplary male mandrel 24 is shown. Integrated structure 23 is formed inone of a plurality of construction stages during creation of crew restberth 10. Male mandrel 24 is constructed of a material structurallysufficient to retain the desired shape of crew rest berth 10 during thisconstruction stage. For example, male mandrel 24 can be made from ametal material such as aluminum or a polymeric material. An inner moldline surface 26 of crew rest berth 10 is defined by a perimeter shape ofmale mandrel 24. Inner mold line surface 26 therefore defines asubsequent inner boundary of crew rest berth 10. Male mandrel 24 canextend beyond the ends of crew rest berth 10 as shown or can be sized tosubstantially equal the berth length “A” of crew rest berth 10. Aplurality of filament windings 28 are wound about male mandrel 24 toform the wall thickness and the general shape of crew rest berth 10 in aprocess further detailed as follows.

As best seen in FIG. 3, a filament application device 30 is provided toshow one example of equipment that can be used to automatically installfilament windings 28. In this example, filament application device 30includes a mandrel support section 32 and a filament application section34. Mandrel support section 32 further includes a head stock 36 and atail stock 38 both supported by stock support legs 40. A mandrellongitudinal axis 42 is formed through male mandrel 24 when male mandrel24 is rotatably supported between head stock 36 and tail stock 38. Malemandrel 24 can be rotated by head stock 36 in either of the directionsof mandrel arc of rotation “D”. Rotational torque for driving malemandrel 24 via head stock 36 is provided by, for example, an electricmotor (not shown).

Filament application section 34 further includes an application head 44which directs placement of the plurality of filament windings 28 aboutmale mandrel 24. Application head 44 can travel in either of thedirections of mandrel displacement arrows “E”. As will be evident to askilled practitioner, application head 44 is also displaceable eithertoward or away from male mandrel 24 and in either an upward or downwarddirection as viewed in FIG. 3.

Filament windings 28 are fed to application head 44 via a head driver 46which also functions to displace application head 44 as required. Bothapplication head 44 and head driver 46 are movably supported on a headsupport frame 48 which in turn is supported for motion in the directionof mandrel displacement arrows “E” by a pair of support legs 50.

A computer 52 which can be either locally or remotely positionedrelative to application head 44 and head driver 46 is provided to permitpreprogrammed operational movement of application head 44. One or morecomputer programs can be programmed into computer 52 for one or aplurality of geometries of male mandrel 24, varying thicknesses orwidths of filament windings 28, varying quantities of layers of filamentwindings 28 and various patterns for applying filament windings 28.Computer 52 provides for automated assembly of crew rest berths 10 thusreducing manpower required for construction of crew rest berths 10.Individual filament windings 28 can also be applied manually to malemandrel 24 if the geometry of male mandrel 24 does not permit automaticapplication via application head 44.

Referring generally to FIG. 4, male mandrel 24 is shown having a portionof a first layer 53 of filament windings 28 applied thereon. A filamentportion 54 supplied by application head 44 of filament applicationdevice 30 is applied to male mandrel 24 as male mandrel 24 rotates aboutmandrel longitudinal axis 42 in a first one of the arcs of rotation “D”.It is desirable to install filament windings 28 as a continuous filamentmember for each wall thickness layer to reduce a total number offilament joints. Application head 44 is translated in the generaldirection of arrow “F” which is timed with the rotation speed of malemandrel 24 to apply one or more individual layers of abutting oroverlapping filament windings 28. A release agent 55 can be applied tomale mandrel 24 prior to or during application of filament windings 28to subsequently aid in releasing integrated structure 23 from malemandrel 24.

Referring generally to FIGS. 5 through 8, a plurality of individuallayers and layering techniques are shown for installation of filamentwindings 28. In one embodiment shown in FIG. 5, a single layer ofoverlapping filament windings 28 is provided by overlapping successivefilament windings 28 using a plurality of overlapped portions 56. Thisembodiment provides for bonding between adjoining ones of the filamentwindings 28. In the embodiment shown in FIG. 6, filament windings 28generally abut with each other, providing a plurality of abutting joints58. This embodiment is particularly suited for applications havingmultiple layers of filament windings 28.

As best seen in FIG. 7, a multiple layer embodiment of filament windings28 is shown. A first layer or ply 60 is applied to male mandrel 24 asshown. A second ply 62 and a third ply 64 are then successively appliedover first ply 60. In this embodiment, filament windings 28 are appliedhaving a plurality of the abutting joints 58. Filament windings 28 ofeach ply can be aligned over successive plies, crossed, for example in aherring-bone arrangement, or perpendicularly arranged. Filament windingjoints between layers of filament windings can be aligned or preferablystaggered. Additional plies (not shown) can also be provided to achievea desired stiffness or strength. FIG. 7 also shows an exemplary berthunit support fitting 65 which can be at least partially overlappedduring the filament application process such that support fitting 65 isstructurally connected to at least one of first, second and/or thirdplies 60, 62 and 64 with or without the use of additional fasteners (notshown).

In a further embodiment shown in FIG. 8, a first or base ply 66 offilament windings 28 is applied to male mandrel 24. At least one coreply 68 is then applied over base ply 66. In one embodiment core ply 68is a honeycomb layer of material having a plurality of honeycomb-shapedcells 69. Core ply 68 has a core ply thickness “G” which is built up ofmultiple layers of cells 69 or formed at least equal to a single layerthickness of filament windings 28, and preferably greater than a singlelayer thickness of filament windings 28. The purpose for core ply 68 isto increase a total ply thickness “H” to stiffen the configuration ofcrew rest berth 10 and also to at least locally provide additionalthickness for further installation of items including fasteners andsupported equipment within crew rest berth 10. It is desirable that coreply 68 be thicker (core ply thickness “G”) than any one filament winding28 but yield the same or a lower weight in an equivalent width offilament windings 28. An exemplary material for core ply 68 is NOMEX®,which is available from the DuPont Corporation. At least one overlyingply 70 is then applied over core ply 68.

After the desired number of layers of filament windings 28 and/or coreply 68 are applied to male mandrel 24, male mandrel 24 is then placed inan autoclave or oven. A temperature within the autoclave is raised to asufficient temperature to bond and harden each of the layers andfilament windings 28 into the general shape of integrated structure 23.Each filament winding 28 is pre-impregnated with an adhesive materialwhich is heat activated at the elevated temperature within the autoclaveto bond into integrated structure 23 (shown in FIG. 2). An exemplaryautoclave temperature range is approximately 134-162° C. (300-350° F.)for curing phenolic material or phenolic containing adhesive materials,and length of cure time is variable from one to in excess of 10 hours.As will be obvious to the skilled practitioner, cure temperature andtime can vary depending on the number of layers and thickness offilament windings 28.

Male mandrel 24 with cured windings 28 in the form of integratedstructure 23 is then removed from the autoclave (not shown) and the malemandrel 24 is then removed from integrated structure 23. Male mandrel 24can be removed in a number of ways, including providing male mandrel 24in a plurality of pieces or segments which can be disassembled forremoval from integrated structure 23. Male mandrel 24 can also beslightly tapered in a longitudinal direction such that the release agent55 applied between male mandrel 24 and the first layer of filamentwindings 28 permits male mandrel 24 to be slid out of contact withintegrated structure 23. Further techniques can also include coolingmale mandrel 24 to shrink male mandrel 24 away from integrated structure23 or longitudinally cutting integrated structure 23 to allow removalfrom male mandrel 24. Cutting integrated structure 23 to remove it frommale mandrel 24 is less desirable because an additional joint resultswhich must then be re-joined for example by adhesive, requiringadditional application and cure times with possibly reduced structuralintegrity.

Referring now to FIG. 9, a pair of crew rest berths 10 including a firstberth 72 and a second berth 74 are shown installed within an aircraft 75and supported from a plurality of structural support members 76. In thisembodiment, structural support members 76 reflect frames of aircraft 75.A berth assembly 71 formed by first and second berths 72, 74 can besupported by any type of structural support member 76 of aircraft 75.One of the advantages of the present disclosure includes that a reducedquantity of connecting fittings 78 can be used to support each crew restberth 10 of berth assembly 71 to structural support members 76.Connecting fittings 78 (and similar connectable items) are preferablyconnected to crew rest berth 10 by overlapping at least a portion ofconnecting fittings 78 below or between layers of filament windings 28during application of filament windings 28.

The reduced quantity of connecting fittings 78 is achievable due to thereduced weight of each crew rest berth 10 manufactured by the processdescribed herein. In one embodiment, a weight of each crew rest berth 10is approximately 75 pounds (34 kg) or less which permits each crew restberth 10 to be manually lifted into place to form berth assembly 71. Bysubsequently interlocking first and second berths 72, 74, berth assembly71 is completed.

Referring specifically to FIG. 10, an exemplary arrangement havingadditional items connectible to first berth 72 is shown. One or morecomponent attachment structures 80 can be applied to any of thenon-adjoining walls of berth assembly 71. Component attachmentstructures 80 permit the further attachment of items such as systempiping, electrical cabling, ventilation ducting, etc., which aresupported to one of the berths of berth assembly 71. Each crew restberth 10 can also be provided with an access panel 82 which in theembodiment shown is connected to an end wall 84. As noted above, each ofthese items are preferably connected to crew rest berth 10 by overlayingat least a portion of the item with filament windings 28 duringapplication of filament windings 28.

Referring generally to FIG. 11, an exemplary connection is shown betweenend wall 84 and each of first and second walls 12, 14. A firstconnecting joint 86 is created adjacent a distal end 87 of crew restberth 10. Similarly, a second connecting joint 88 is created adjacentdistal end 87 of crew rest berth 10 of second wall 14. In oneembodiment, each of first and second connecting joints 86, 88 are formedby removing a pre-determined amount of total ply thickness “H”. A firstconnecting end 90 of end wall 84 and a second connecting end 92 of endwall 84 are overlapped with first and second connecting joints 86, 88,respectively. An adhesive 94 is applied at each junction between endwall 84 and the connecting joints of crew rest berth 10. End wall 84 isconnected in a similar manner to each of first and second side walls 16,18 of crew rest berth 10. These joints are redundant and therefore notshown for simplicity.

Connecting joints 86, 88 are preferably created using an automatedmachining process to minimize labor time. Connecting joints 86, 88 canalso be formed by hand removal of the material. Additional embodiments,not shown, include having first connecting end 90 of end wall 84 andsecond connecting end 92 of end wall 84 sized to either overlap or slidewithin unmodified ends of crew rest berth 10 and adhesively sealed.

Referring to FIG. 12, the operations for creating a mobile platformpersonnel berth include the operations of: supplying a male mandreldefining an inner mold line surface of a berth unit (100); applying atleast one filament strip to the male mandrel to create at least onefilament layer (102); thermally curing the at least one filament layerto create an integrated structural member (104); and removing the malemandrel from the structural member (106).

Referring to FIG. 13, according to another embodiment of the presentdisclosure, the operations for creating a mobile platform personnelberth include the operations of: creating a male mandrel defining aninner mold line surface of a berth unit (110); applying a first filamentply over the male mandrel (112); covering the first filament ply with acore ply (114); overlaying the core ply with at least a second filamentlayer (116); curing the filament layers to create an integratedstructural member (118); and removing the male mandrel from thestructural member (120).

Material for filament windings 28 is preferably predominantly a graphite(carbon) base material pre-impregnated with an adhesive portion. Aphenolic adhesive is used in one preferred embodiment. A source forfilament windings 28 in pre-impregnated form is Cytec EngineeredMaterials, Inc., of Tempe, Ariz. Use of graphite material provides highstrength and reduced weight compared to common crew rest berths. Atleast one and preferably approximately three layers of filament windings28 are used. Less than three or more than three layers can be used atthe designer's discretion. The present disclosure is not limited to theuse of graphite material for filament windings 28 or to the number offilament winding or core ply layers. Other materials such as fiberglassand alternate polymeric materials or composite materials can be used.Phenolic material or phenolic material with one or more additives whichmeet flammability standards is one preferred material group for theadhesive used to bond the filament strips in applications such asaircraft interiors where flammability requirements are invoked.

A filament wound crew rest enclosure structure of the present disclosureprovides several advantages. By integrally joining the walls, top andbottom surfaces of a crew rest enclosure, the number of connectingfittings is reduced. By using one or more filament wound layers of agraphite and/or graphite/polymeric material a weight of the crew restenclosure can be reduced to about 75 pounds (34 kg) or less, whichpermits two mechanics to manually install the crew rest enclosurewithout the need for special handling equipment. By using an automatedcomputer controlled tape laying machine, construction time is reducedcompared to the known process of forming individual panels and manuallyjoining the panels using a plurality of connectors and fasteners.

While various embodiments have been described, those skilled in the artwill recognize modifications or variations which might be made withoutdeparting from the inventive concept. The examples illustrate thepresent disclosure and are not intended to limit it. Therefore, thedescription and claims should be interpreted liberally with only suchlimitation as is necessary in view of the pertinent prior art.

1. A mobile berth unit for an aircraft and adapted to accommodate anindividual, comprising: a body attached to an internal wall portion ofthe aircraft and having integrally joined perimeter walls defining asubstantially hollow interior space; and a wall thickness operablyformed from at least one layer of a continuously wound filament; an endwall attached to the body at one end thereof; and wherein a material ofthe body contains a substantially graphite material.
 2. The berth unitof claim 1, wherein the substantially graphite material furthercomprises a polymeric portion.
 3. The berth unit of claim 2, wherein thepolymeric portion comprises a phenolic adhesive material preimpregnatedon the graphite material.
 4. The berth unit of claim 1, wherein theintegrally joined perimeter walls of the four-sided body comprise a top,a bottom and an opposed pair of side walls.
 5. The berth unit of claim1, further comprising a plurality of hardware bonded to the filament ofthe berth unit and operable to support both a weight and a dynamic loadof the berth unit.
 6. The berth unit of claim 1, wherein the wallthickness further comprises a plurality of layers of wound filaments. 7.The berth unit of claim 1, wherein the wall thickness further comprises:an inner ply having at least one layer of the wound filament; a core plyoverlying the inner ply; and at least one outer ply having at least onelayer of the wound filament overlying the core ply.
 8. The berth unit ofclaim 7, wherein the core ply comprises a honey-comb shaped structure.9. A berth unit for an aircraft and adapted to accommodate anindividual, the berth unit comprising: a body portion attached to aninternal wall portion of the aircraft having integrally formed perimeterwalls including top, bottom, and a pair of side walls forming agenerally continuous, seamless portion, sufficient in size to enable anindividual to enter an interior area thereof; said body portion having awall portion formed by at least one layer of a continuously woundfilament extending in a plurality of unbroken turns around a fullcircumference of said body portion; and an end wall attached to one endof said body portion.
 10. The berth unit of claim 9, further comprisingan attachment structure secured to one of said perimeter walls.
 11. Theberth unit of claim 9, wherein said filament comprise a graphitematerial.
 12. The berth unit of claim 9, wherein said filament furthercomprises a polymeric portion.
 13. The berth unit of claim 9, whereinsaid polymeric portion comprises a phenolic adhesive material.
 14. Theberth unit of claim 9, wherein said wall portion further includes a coreply sandwiched between a pair of layers of wound filaments.
 15. Theberth unit of claim 14, wherein said core ply comprises a honeycombconstruction.
 16. A berth unit for an aircraft adapted to accommodate anindividual and adapted for placement in an overhead area within theaircraft, the berth unit comprising: a body portion attached to astructural portion of the aircraft and having integrally formedperimeter walls including top, bottom and side walls forming a generallycontinuous, seamless portion; said body portion having a wall portionformed by at least one layer of a continuously wound filament; an endwall attached to one end of said body portion; and at least oneconnecting fitting integrally coupled to said body portion duringmanufacture of said body portion.
 17. The berth unit of claim 16,wherein said wall portion is formed by a plurality of layers of acontinuously wound filament.
 18. The berth unit of claim 17, whereinsaid wall portion includes a core ply having a honeycomb construction,said core ply being sandwiched between a pair of layers of saidcontinuously wound filament during construction of said body portion.